1. Field of the Invention
The present invention relates to a molding installation using a die and, more particularly, to an automatic molding installation having a layout suitable for an automatic operation capable of exchanging or conveying a die to be set in a molding apparatus.
2. Description of the Prior Art
Conventional molding equipment using a die includes one, for example, for a metal mold casting, a press molding, and a plastic molding. As a plastic molding is known an injection molding, a compression molding, a blow molding and so on.
Molding apparatus of various types for those moldings are known to those skilled in the art and they require a lot of time and labor in a die exchanging operation. A die is so heavy that it is very difficult and risky to exchange the die using labor only.
Heretofore, various methods have been employed for exchanging a die for an old one in a molding apparatus. For example, Japanese Utility Model Publication No. 2,537/1983 discloses a die exchange using a crane. This technology would be effective in an automatic conveyance of the die to the molding apparatus from a stocker in which the die has been stored although it would be effectively applicable to the die exchanging operation. The disadvantage prevailing in these technology using a crane system, however, underlies in the fact that a long time of labor work involving risk is inevitably required for hoisting dice with cranes.
Different technology is disclosed in Japanese Utility Model Publication Nos. 2,537/1983 and 5,557/1984, Japanese Patent Publication (Laid-Open) No. 48,132/1984 (Japanese counterpart of West German P3 222 743.4 and P3 242 169.9) and Japanese Patent Publication (Laid-Open) No. 201,624/1983 (Japanese counterpart of West German G8 212 045 and P3 220 911.8). This technology is directed to methods of exchanging a die through a table disposed on the side of a molding apparatus. This technology has the advantage that the die can be exchanged in a state of being loaded on the table without labor as required for conventional crane systems, thus leading to a stable die exchanging operation. It is to be noted that this technology is of some help to automating a die exchanging operation for a molding apparatus. None of these prior patent applications, however, disclose any technique for conveying the die to the table on which the die is exchanged. Accordingly, their disclosures are remote from appliction to an automation in a molding installation as a whole system.
It is a matter of course that a molding installation requires a maintenance area where the die is subjected to maintenance, and a function as conveyance of the die between the maintenance area and a molding apparatus.
Maintenance work is done in the maintenance area. However, the position of a die to be brought into the maintenance area may be different from a position of the die loaded in the molding apparatus or stored in the stock area. For the maintenance area, the die is arranged in such a position, that is, in such a standing or erect state, as what is required for maintenance, whichever a front mold (fixed side part) or a rear mold, viz., a movable half of mold, both constituting the die or a mold constituted by both the front and rear molds, is placed above what is not required for maintenance. For a transverse molding apparatus, the die should be placed in such a state that its front and rear molds are juxtaposed or placed side by side, and, for a vertical molding apparatus, the die should be placed in such an erect state or posture as its rear mold is on the top of the front mold or vice verse.
Accordingly, when such a transverse molding apparatus is used for a molding installation, the position of a die to be brought into the maintenance area should be always shifted to a standing position required in the maintenance area. For such a vertical molding apparatus, the position of a die should be shifted to such a position as its mold half required for maintenance being brought above the other mold half when the mold half required for maintenance has been placed underneath the other half.
In conventional techniques, a die conveyed for maintenance is treated usually in the maintenance area using a crane so as to brought its mold half necessary for maintenance on the top of the other half. This work requires a lot of labor involving risk.
Accordingly, there have been great demands for automation in a molding installation to such an extent that no or little labor is required for a die exchanging operation, a die conveying operation between a molding apparatus and a maintenance, and so on.